6) now change to a partial trust environment (for example a mapped network drive to the same folder (in my case the z:\ drive is mapped to \\127.0.0.1\{folder name} ) and note that when executing _readonly.exe you will get the following JIT exception:

Z:\readOnlytest>_readOnly.EXE

Unhandled Exception: System.Security.VerificationException: Operation could deabilize the runtime. at Owasp.ReadOnlyTest.Main()

7) this shows that in partial trust the verification occours and in Full Trust it doesn't

8) you can also use PeVerify to get more details about the problems with _readOnly.exe